Spinal Cord Stimulation and Whiplash Injury

Electrical spinal cord stimulation (SCS) is a technique used to treat a select group of patients with chronic, intractable pain. This case report investigates the effectiveness of SCS on a patient a whiplash-type injury.

The patient had a 4-year history of chronic pain, all stemming from a neck injury. His pain was localized into the left side of pharynx and the base of tongue radiating to the left cheek and ear. In course of his treatment heavy medications, physiotherapy, TNS-treatment, trigger joint injections, and stellate ganglion block were all tried but to no benefit. At this point, the treating physicians decided to try epidural spinal cord stimulation:

"As it is important to achieve stimulation paresthesias in the topographical representation of the patient's pain, we were forced to advance the tip of the electrode to the level of the base of the dens until satisfactory paresthesias were achieved. Interestingly, the first subjective feeling from stimulation was a warm, almost burning sensation over the previously painful area. During the trial stimulation pain symptoms started to disappear. First to give way were allodynia and hyperesthesia around the left ear. Last to disappear were the lancinating sensations, which sporadically appeared even a few weeks after the internalization of the system."

"SCS is an expensive and invasive way to treat pain. However, in addition to relieving pain and improving the quality of life of out patient, it has already caused considerable savings�Our case shows that SCS can offer an alternative treatment in whiplash-type pain syndrome of this complexity."

At last assessment, the patient had been without pain and analgesics for 18 months.

What causes radicular pain after an auto collision?

Radicular pain, or radiating pain, is caused by interference or pinching of the spinal nerves. This results in pain, tingling, or numbness in parts of your body far from the actual source of the problem.

If your spine is injured, there are a number of things that can affect the nerves.Injured ligaments and muscles can cause inflammation of the nerve root, which can disrupt the function of the nerve. If a spinal disk is damaged, it can cause the disk to bulge or herniate, pinching the nerve. And if the spinal joints begin to calcify, it can cause spinal stenosis, or a narrowing of the canal that the spinal nerves pass through.

All this can lead to a number of conditions such as sciatica, carpal tunnel syndrome, low-back pain, shoulder pain, and more. It's crucial to treat these conditions to prevent further nerve damage or worsening symptoms.

The key to treating radicular pain is to pinpoint its source in the spine. After determining the root of your pain, a chiropractor can relieve pressure on the impinged nerves. This allows the nerves to heal by reducing inflammation and irritation.

Whiplash or Fibromyalgia?

A recent study published in the journal Pain sheds some light on the ongoing debate about the causal relationship between neck injuries sustained during a car accident and the development of the pain condition fibromyalgia. Chiropractors commonly treat patients with both conditions, and separating these diagnoses can improve treatment. The latest research suggests that fibromyalgia may be overdiagnosed in patients who have a history of whiplash injury due to a motor vehicle accident.

People with fibromyalgia experience a range of life-disrupting symptoms, include general and localized pain, fatigue, and difficulty sleeping. Neck and shoulder tenderness is one common indicator that practitioners use to diagnose fibromyalgia; general pain lasting longer than three months is another. However, these symptoms also are common among patients experiencing the lingering effects of whiplash. Some past research has shown that people with neck injuries incurred in a motor vehicle accident are 13 times more likely to develop fibromyalgia than those with other injuries. Other studies have questioned these conclusions.

Researchers at the University of Washington set out to investigate the prevalence of fibromyalgia in whiplash patients with persistent neck pain. They questioned whether the most common set of criteria used for diagnosing fibromyalgia may rely too heavily on evaluating trigger points located in the neck and shoulder. The study participants included 326 individuals with whiplash-associated neck pain that had lasted longer than 3 months. The participants were enrolled in a 6-week treatment program for their symptoms that consisted of educational therapy sessions.

The researchers evaluated the patients for fibromyalgia both at the beginning and the end of the program. Two sets of criteria were used to diagnose fibromyalgia: the standard guidelines and adjusted guidelines that discounted the importance of pain in the neck and shoulder area. Using the standard guidelines, the researchers initially diagnosed 14% of the whiplash participants with fibromyalgia. This rate dropped to 8% using the adjusted guidelines.

These findings suggest that health practitioners who treat patients with persistent neck pain, such as chiropractors, may be led to significantly overdiagnose fibromyalgia in their patients. People with a history of whiplash-associated injuries should be aware of this unintended bias, and report their injury history.

Motor Vehicle Accidents and TMD

Few published studies have investigated the effect of temporomandibular joint disorders (TMD) and motor vehicle accidents. Since a correlation between the etiology of TMDs and trauma from vehicle accidents is controversial and undetermined, the researchers evaluated 50 files of patients with post-vehicle accident TMD. Evaluating the signs and symptoms, diagnoses, and outcomes, they found evidence explaining the possible effects of the two.

76% of the group identified TMD-related symptoms within one week or less of accident. Symptoms included TMJ or limited jaw opening, headache, neck and back pain. Since almost the entire sample experienced a rear-end or front-end collision, the researchers compared these two predominant groups.

The front-end collision patients reported jaw locking more frequently, and direct injuries to facial and dental areas; but the group required a fewer number of treatment types and experienced less tenderness over time.

Patients in the rear-end collision group were the opposite: they received more treatment types and reported masticatory tenderness during the final examination. Similarly, although the patients involved in severe vehicle accidents experienced more head, facial, and dental injuries, patients involved in minimal damage accidents reported more treatment visits and had higher rates of tenderness than with severe damage.

After assessing the accident and impact factors, the researchers found a slower recovery in those collisions with: minimal vehicle damage, lack of headrest use, poor driver position, and settlement of claim. This last finding is particularly interesting, as litigation is usually believe to prolong symptoms: "...insurance claim settlement at the time of the initial visit did not seem to suggest a better prognosis for patients with post-MVA TMDs..."

While discussing the onset of symptoms, the researchers concluded:

"We find it troubling that TMJ symptoms were identified by the patients themselves (rather than by health care providers) for over 80% of the study patients. Nondental health care workers must heighten their awareness of the possibility of TMD-related problems occurring in the MVA patient..."

Chiropractic Treatment of Spinal Fracture

Two recent studies have been published that discuss the successful management of spinal fractures with chiropractic treatment.

The first1 describes the case of a 49-year-old man who, after a fall on his buttocks, developed an "oblique (zone III) fracture through the fifth sacral segment with slight anterior displacement of the distal fragment."

"Neurological examination was unremarkable. On orthopaedic examination, the buttock pain was elicited by stressing the sacroiliac (SI) joints, but the distal sacral pain was not aggravated. Patrick's test was negative."

"Palpation revealed marked tenderness of the distal sacrum. Both SI joints were tender and hypermobile. Palpation of the lumbosacral and gluteal musculature did not recreate the patient's symptoms."

"After obtaining the patient's informed consent, the SI joints were manipulated with the patient in side-posture, once on each side, with a contact over the proximal SI joint. Interferential current was applied over the sacrum for analgesia. The patient felt markedly improved immediately."

Further chiropractic treatment consisted of four daily treatments, and then five more treatments during the next two weeks. At that time the patient was discharged.

In the second case2, the authors describe the case of a 18-year-old man with a Chance fracture of L3. The man was sitting in the middle rear seat of a car that hit a tree. He was taken by ambulance to the emergency room, where the resident physician told him that radiographic findings were normal. He reported low back pain and paresthesia in the left leg. He was given pain medications and sent home.

The patient had the same symptoms 3 days later, but was again told that everything was normal. An orthopaedic surgeon then evaluated the radiographs and diagnosed a "nondisplaced fracture of L3 confined to the posterior fourth of the vertebral body."

The patient was brought to the chiropractic physician twelve days after the accident. "The chiropractic interpretation of the radiographic examination contradicted the opinion verbally provided by the orthopedist at the hospital. Plain films demonstrated a Chance fracture of L3, extending from both laminae through the pedicles and transverse processes and continuing into the posterior-inferior portion of the vertebral body of L3, passing through the inferior end-plate. It was clear that there was a posterior displacement of the posterior-inferior aspect of the upper part of the L3 vertebral body."

After careful examination of radiographs and CT images, chiropractic treatment was instituted.

"After the second adjustment to L3, the paresthesia to the left leg had resolved and the low back pain had reduced considerably. The patient was adjusted on three occasions at L3 over the course of a week...Approximately 1 month after beginning chiropractic care, the patient reported that the leg symptomatology, including the uncontrollable knee flexion, was very much improved."

At four months after the accident, the patient had no paresthesia in the left leg, and had occasional minor low back pain.

The authors of both studies warn that extreme caution should be observed when working with severe spinal trauma. We recommend that those interested in these studies obtain complete copies for themselves.

Steiman I, Grod JP. Spinal manipulation in a case of sacral fracture: presentation in a chiropractic office. Journal of the Canadian Chiropractic Association 1996;40(3):145-149.

Plaugher G, Alcantara J, Hart CR. Management of the patient with a Chance fracture of the lumbar spine and concomitant subluxation. Journal of Manipulative and Physiological Therapeutics 1996;19(8):539-551.

Whiplash Symptoms - Low Back Pain

Over the last 10 years, hundreds of studies have been done on the problem of whiplash, and most of those studies have focused on the most common symptom of the diagnosis: neck pain. This concentration of research has resulted in a clear understanding of how a rear-end collision can result in injury.

Shear forces occur when one part of the spine moves in one direction while another part of the spine moves in a different direction.

Shear forces can cause tearing or stretching of the soft tissues that hold the spine together.

The primary reason why rear-end collisions cause injury is that the human spine is designed to withstand vertical forces, while a rear-end collision is a horizontal force. The vertical forces are known as “axial” forces. The horizontal forces, known as “shear” forces, cause unnatural movements of the cervical spine and can result in damage to the ligaments of the neck.

A new study has now shown that a similar injury mechanism occurs in the lumbar spine as well. Inspired by the research on the cervical spine, the authors of this study applied the same methodology to the low back.

They placed a cadaver in a standard automotive seat and placed acceleration-measuring devices in the vertebral bodies of T1, L1, L3, and L5. The seat was placed on a platform that was subjected to rear accelerations of 5g and 8g, or speeds of approximately 8 and 12 mph, respectively. The researchers collected acceleration data at a rate of 10,000 samples per second. Radiographs were taken of the spine before and after the tests. The study found that different parts of the lumbar spine experience different strains during a rear-end impact:

“The anterior shear strains had mostly a biphasic response. Spinal strains started at about 30 msec after impact and peaked at the T12 vertebra at approximately 120 and 370 msec, whereas in the L4 vertebra, it peaked at 200 and 380 msec. The anterior strain patterns of the L4 and T12 vertebrae were in diametrically opposite directions.”

The direction and strength of the forces suggests that the car seat rapidly accelerates into the occupant’s spine, causing the thoracic and lumbar curves to straighten.

The authors of the study carefully examined the forces involved in the spine during the test impacts. They found that the car seat exerted about 1500 Newtons (approximately 337 pounds) of force, in a fraction of a second. The authors relate this to how the lumbar spine can be injured in rear end collisions:

“In the current study, no bony injuries were observed in the lumbar spine, either by visual inspection or by radiographic studies. In the absence of clear bony pathology after rear-impact collision, we propose that irritation of or injury sustained by the richly innervated spinal soft tissues (i.e., muscles, ligaments, capsules) plays an important role in the pathogenesis of lumbar pain after whiplash injury. This proposition is supported by work of others who performed lumbar spinal segment shear tests and showed that soft-tissue injuries occurred with a shear load as low as 1200 N.”

The 1500 Newtons of force was reached in the 5g test, which was equivalent to an 8 mph collision. So, according to this preliminary study, the car seat back exerts enough force during such a collision to injure the connective tissue of the lumbar spine.